inverse of matrix 18x18

A=[0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0.960000000000000	0	0	0	0	-0.960000000000000	0	0	0	0	0	0	0	0	0	0	0;
0	0	2.23790608695652	0	0	0	0	0	-1.33550608695652	0	0	0	0	0	0	0	0	0;
-1.24547021739130	0	0	25.4935942611344	-11.6040718529838	-10.5106639714776	0	0	0	0	0	0	3.30740954238180	1.36517736605472	1.94219279132692	0	0	0;
0	0	0	-11.6040718529838	3.59689473818280	0	-5.97512017854242	0	0	0	0	0	1.36517736605472	2.55280007950317	0	1.18760382787156	0	0;
0	0	0	-10.5106639714776	0	2.11657463928156	0	0	-5.58823079251630	0	0	0	1.94219279132692	0	3.22418780554366	0	0	1.28201098652570;
0	-0.960000000000000	0	0	-5.97512017854242	0	6.65075604340637	-13.6979757743444	0	0	0	0	0	1.18760382787156	0	2.80471238660181	1.61711697025140	0;
0	0	0	0	0	0	-13.6979757743444	-5.54012668752085	-9.78425422305323	0	0	0	0	0	0	1.61711697025140	2.77219546898122	1.15508187530801;
0	0	-1.33550608695652	0	0	-5.58823079251630	0	-9.78425422305323	-12.3143655823924	0	0	0	0	0	1.28201098652570	0	1.15508187530801	2.43710327055050;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	-3.30737015738164	1.36517736605472	1.94219279132692	0	0	0	0	0	0	55.5915770671030	-11.6040718529838	-10.5106639714776	0	0	0;
0	0	0	1.36517736605472	-2.55276150142619	0	1.18760382787156	0	0	0	0	0	-11.6040718529838	33.6949232068892	0	-5.97512017854242	0	0;
0	0	0	1.94219279132692	0	-3.22418448881414	0	0	1.28201098652570	0	0	0	-10.5106639714776	0	32.2146426775241	0	0	-5.58823079251630;
0	0	0	0	1.18760382787156	0	-2.80471913975820	1.61711697025140	0	0	0	0	0	-5.97512017854242	0	66.8288576325249	-13.6979757743444	0;
0	0	0	0	0	0	1.61711697025140	-2.77220222213760	1.15508187530801	0	0	0	0	0	0	-13.6979757743444	54.6379749015977	-9.78425422305323;
0	0	0	0	0	1.28201098652570	0	1.15508187530801	-2.43709623841190	0	0	0	0	0	-5.58823079251630	0	-9.78425422305323	79.3225061858399]

its 18x18 matrix, i want to find inverse

i tried with inv(A) but it shows "Warning: Matrix is singular to working precision."

then it shows all elements are "inf"

i want to invert it for further calculation

Answer 1

[M.Many]

The inverse doesn't exist because A is singular, this means that one or more rows are linearly dependent from other rows. A is inversible if and only if det(A) =/= 0. However, the determinant of A is 0 here.

Answer 2

[Walter Roberson]

format long g
A=[0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0.960000000000000	0	0	0	0	-0.960000000000000	0	0	0	0	0	0	0	0	0	0	0;
0	0	2.23790608695652	0	0	0	0	0	-1.33550608695652	0	0	0	0	0	0	0	0	0;
-1.24547021739130	0	0	25.4935942611344	-11.6040718529838	-10.5106639714776	0	0	0	0	0	0	3.30740954238180	1.36517736605472	1.94219279132692	0	0	0;
0	0	0	-11.6040718529838	3.59689473818280	0	-5.97512017854242	0	0	0	0	0	1.36517736605472	2.55280007950317	0	1.18760382787156	0	0;
0	0	0	-10.5106639714776	0	2.11657463928156	0	0	-5.58823079251630	0	0	0	1.94219279132692	0	3.22418780554366	0	0	1.28201098652570;
0	-0.960000000000000	0	0	-5.97512017854242	0	6.65075604340637	-13.6979757743444	0	0	0	0	0	1.18760382787156	0	2.80471238660181	1.61711697025140	0;
0	0	0	0	0	0	-13.6979757743444	-5.54012668752085	-9.78425422305323	0	0	0	0	0	0	1.61711697025140	2.77219546898122	1.15508187530801;
0	0	-1.33550608695652	0	0	-5.58823079251630	0	-9.78425422305323	-12.3143655823924	0	0	0	0	0	1.28201098652570	0	1.15508187530801	2.43710327055050;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0;
0	0	0	-3.30737015738164	1.36517736605472	1.94219279132692	0	0	0	0	0	0	55.5915770671030	-11.6040718529838	-10.5106639714776	0	0	0;
0	0	0	1.36517736605472	-2.55276150142619	0	1.18760382787156	0	0	0	0	0	-11.6040718529838	33.6949232068892	0	-5.97512017854242	0	0;
0	0	0	1.94219279132692	0	-3.22418448881414	0	0	1.28201098652570	0	0	0	-10.5106639714776	0	32.2146426775241	0	0	-5.58823079251630;
0	0	0	0	1.18760382787156	0	-2.80471913975820	1.61711697025140	0	0	0	0	0	-5.97512017854242	0	66.8288576325249	-13.6979757743444	0;
0	0	0	0	0	0	1.61711697025140	-2.77220222213760	1.15508187530801	0	0	0	0	0	0	-13.6979757743444	54.6379749015977	-9.78425422305323;
0	0	0	0	0	1.28201098652570	0	1.15508187530801	-2.43709623841190	0	0	0	0	0	-5.58823079251630	0	-9.78425422305323	79.3225061858399];

rank(A)

ans = 
    14

Not even close -- only 14 out of 18

A([1 10 11 12], :)

ans = 4×18

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

●

You have four rows that are all zero. Also columns 10 11 12 are all 0. Any time you have a row or column that is all zero, you are guaranteed that the matrix is singular.